STRUCTURE AND DISTRIBUTION OF PEYERS-PATCHES IN THE INTESTINE OF TUPAIA-BELANGERI THOMAS, 1914

The small intestine of the tupaias (n = 10) studied contains a mean of 15 +/- 1 Peyer's patches (PP), that usually lie in antimesenteric pos ition. The area of aggregated lymphoid follicles reaches nearly 3% of the small intestinal surface. All lymphoid patches of an individual co nsist of a mean of 528 +/- 56 follicles. A few large PP with many lymp hoid follicles are scattered in the mid portion of the small intestine . Many smaller patches lie in the first and last third of the small in testine. The PP area and its number of lymphoid follicles were related with the surface of intestinal segments that surround the patches. Be tween the PP dimensions and the appertaining surface of the small inte stine exists a constant relation along the small intestine. Tree shrew s' PP are composed of five different regions: follicle-associated epit helium (FAE), dome, corona, germ centre and interfollicular area. Endo crine cells of the FAE differ in cellular structure from endocrine cel ls of the ordinary intestinal epithelium. The present findings are com pared and discussed with corresponding results in other mammals.